howlett



O ct. 22, 1929. w. E. HOWLETT AUTOMATIC HOIST Filed May 5, 1927 2 Smets-Sheet v///////////////////////////IlWA llllll Oct. 22, 1929.

w. E. HowLt-:TT 41,7325232 AUTOMATIC HOIST med may 5, 1927 z sheets-snm 2 4 A wma/lef #www i@ Mr, MW, QW YWWS Patented Get. 22, 1929 I UNlTil) STATES PATENT OFFICE WILLIAM E. HOWLETT, 0F MOLINE, ILLINOIS, ASSIGNOR TO HOWLETT CONSTRUCTION COMPANY, OF MOLINE, ILLINOIS, A CORPORATION OF ILLINOIS AUTOMATIC HOIST Application filed May 5,

This invention relates to an automatic hoist. It is particularly applicable to railway coaling station hoists but it may be also applied to hoists used for other purposes.

Automatic coaling hoists usually include an engine or electric motor driven hoisting drum over which passes a cable connected at one end to a hoisting bucket and the other end to a counterweight. When an electric motor is used switch devices are provided for reversing it to reverse the direction of rotation of the drum to raise the bucket up and down in the hoisting tower, and a brake is employed ior stopping the hoisting apparatus at the time the reversal takes place. It will be evident that, with the hoisting drum located above the bucket and with the cable passing from the bucket over the drum to the counterweight without being wound about the drum, if the bucket is grounded or if its weight is relieved from the cable in any other manner, the cable will be slackened and its grip or traction on the drum will be destroyed so that the hoisting drum will spin relative to it. This soon wears out the cable and is such an undesirable condition that it has been considered impractical to locate the hoisting apparatus above the hoisting bucket where a slackening ot the cable will result in the spin ning of the drinn relativo to it. Instead, the hoisting apparatus has been mounted oiii at one sido and below the top ot the hoisting tower and the hoisting cable has tirst been passed over pulleys and then down to the drum oit the hoisting apparatus as illustrated, for example, in Fig. 5 ot' my prior Patent :ii-1,592,602, .i uly 13, 1926. rlilhis not only requires a longer cable and more parts, but it also introduces more Jfriction inthe apparatus and makes necessary the building of an addition to 'the hoisting tower to house the hoisting apparatus.

The present invention is directed to the provision of an improved automatic hoist in which the hoisting apparatus may be mounted in the top of the tower above the hoisting bucket and slackening of the cable prevented when the weight of the bucket is temporarily relieved from the cable.

1927. seal No. 188,885.

The general object of the invention is to provide an improved automatic hoist.

A more particular object is to provide an improved automatic coal hoist in which the hoisting apparatus is located in the hoisting tower above the hoisting bucket.

A still further object is to provide, in a hoisting apparatus ot the kind described, means tor automatically preventing the hoisting cable from being slackened when the weight on one end of the cable is relieved.

Another object is to provide a means for automatically applying additional force to cause the descent of a hoisting bucket when the same is obstructed during its descent.

Other objects and advantages of the invention will hereinafter appear.

An embodiment of the invention is shown in the accompanying drawings in which:

Figure 1 is a side elevation and section of the automatic hoist showing the hoisting bucket in lowered position;

Fig. 2 is a similar side elevation oi' a portion of the hoist showing the hoisting bucket in the position it occupies when it is opening the door that permits coal to flow into the bucket;

Fig. 3 is a side elevation showing the position of the parts when the bucket is being dumped at the top of the hoisting tower;

Fig. 4 is a side elevation of the hoist-ing bucket taken at right angles to Fig. 2.

The hoisting bucket and the electrical hoi sting apparatus employed in the present invention are of the type disclosed in my prior Patent No. 1,592,602, July 13, 1926, and they will be described only briefly in this application, reference being made tov said patent and to the improvement thereon shown in Patent No. 1,622,589, March 29, 1927.

The hoisting bucket 10 comprises a rectangular receptacle which is lowered to, and raised from, an opening 11 in the bin 12 in the hoisting tower 13. The opening 11 through which material passes into the bucket when the bucket is lowered is closed by a door 14 normally urged to closed position by weights which are not shown herein but are fully described in the above mentioned prior patents.

This door is opened during the descent of the bucket by the bucket itself whose bottom edge l5 strikes projections 1G on the doorl and carries the door downwardly. The bucket is stopped by the hoist in a proper lowered position for loading which is short ot' the bottom 17 oi' the tower, it not being desirable to ground the bucket during the operation ot the hoist, as 'this would tend to slackcn the cable. Y

, The automatic hoisting apparatus includes a drum rotated by an electric mon tor 21 and stopped by a brake 22. When the hoisting bucket reaches either the bottom or the top oit its path of movement, the electric motor is automatically reversed and 'the brake 22 applied, the Control of these parts being by switching devices well known in the art. The brake 22 isset to stop the bucket at the proper point and a proper time interval is provided in the reversal of the motor to permit the hoisting bucket to be loaded at the bottom oit the tower and to be dumped at the top 'of the tower bei'ore its direction is reversed. The hoisting apparatus is mounted on a 'platform 23 located at the top of the tower 13 and directlyabove the hoisting bucket 1'0 so that the hoisting apparatus is housed within the tower and in a position where its hoisting efforts may be appliedv directly to the bucket.

A hoisting cable 24, preierably having several strands as shown in Fig. l, passes over the drum 20. 'One end of the cable is connected to a counterweight 25 which assists in raising the bucket and keeps the cable tightly in vengagement with the drinn to prevent slipping or, to use the term oni` ployed by engineers, 'to provide traction It will be evident byreterence to Fig. 1 that if either the bucket 10 or the counterw'eight 25 is grounded or its Aweight otherwise relieved `from the cable 24, the cable will be slackened and since the cable merely passes over the drum without passing around it, it will likewise be clear that il the cable is slackened there will be a tendency for the drum to spin relative to`it., This not only wears out the cable rapidlybut it relieves a load from the hoisting 'apparatus and permits it to spin rapidly and to operate in a jerky and undesirable manner. Ordinarily, the counter-weight `25 is free of obstructions and has plenty of room within 4which to operate so that it is never grounded `or its weight otherwise taken from the cable but the weight of tl'iepbucket 10 may be taken from the cable under several circumstances. For example, it may be that, owing to lack of lubrication or because ot some obstruction, the door 14 will not descend easily and, when the bucket strikes the projections 16, its descent is ariestedto such an extent that substantially the entire weight of the bucket, which is then empty, is taken by the door. It may also happen that the brake 22 will ing action occurs at the top of the tower where the trunnions 26 on the hoisting bucket engage in guideways 27 and the upward pull of the hoisting cable turns the bucket to the dumping position ot Fig. ln

this position the most oi the weight of the bucket is 'carried by the guideways 27 and there would be a tendency to slack-en the ible and permit the drum to spin.

fis previously stated, these difficulties have been considered so insurmountable that the mounting of the hoisting apparatus directly above the bucket with the cable passing over the drum as illustrated in F 1, has been considered impractical. Constructions oit this type which have been attempted have been abandoned and the art has almost universally employed constructions oit the type illustrated in Fig. 5 ot my prior Patent No. 1,592,602. The present invention, however, has made possible the success of a hoist in which the hoisting apparatus is mounted directly above the bucket with the cable from the hoisting bucket passing directly over the drum to 'a counterweight.

instead ot connecting the hoisting cable 24 directly'to the bucket 10, it is connected to a weight 30 which is termed a compensating weight. This weight may be or" any suitable type the preferred construction being a long weight oit rectangular cross-section as ih trated in Figs. 1 and t. The weight is provided with. openings 31 in which are loosely mounted rods 32 carried bythe rigid bail 33 pivoted to the hoisting' bucket l0 on the studs 34. The rods 32 have nuts threaded on their ends and washers 35 bear against these nuts to form stops for springs 3G which are interposed between the stops and the top surface of the-weight 30.

Assume that the bucket 10 is arrested during its descent by the door 1li or by some other obstruction such that the weight of the bucket is relieved from the cable to a sufficient extent to ordinarily cause the cable to slacken. With the present invention the cable does not slacken because even though the weight oi the bucket is taken by the door or some other obstruction, the weight 30 maintains a substantial tension on the cable which is amply suiiicient to maintain good traction. Vhen the bucket 10 stops the weight 3() moves downwardly on the rods 32 as illustrated in F 2. It the bucket 10 is held up onlyv momentarily it may again start downward before the weight 30 reaches the end' oie. its travel, but, if the bucket is not released immediately, the weight will move down till it strikes the top of the rigid bail 33. This delivers a sharp blow on the bail, which, under all ordinary circumstances, will loosen the bucket and start it on its travel downward. During this time the weight 30 has maintained tension on the cable 24, the action being in the nature ot' a continuous one, that is7 the weight 30 strikes the bail 33 a sudden blow which drives the bucket on downwardly and permits the weight 30 to continue keeping the cable under tension. 1lWhen the bucket is loosened and when it drops the weight is not again applied to the cable with the sudden jerk but the stop washers strike the springs 36 which cushion the weight of the bucket as it is again applied to the cable.

The weight 30 thus not only serves to keep the cable under tension in the event the bucket is arrested during its descent but it also acts to apply additional torce to cause the bucket to continue its descent. lt is usetul in dislodging the bucket in the event it becomes stuck.

Another condition under vhich the weight acts is in connection with the stopping of the bucket at the bottom ot its travel. The brake 22 acts to stop the hoisting apparatus to stop the bucket in loading position which is short of the bottom 17 of the tower. The distance ot travel of the hoisting apparatus through which the brake must operate is relatively small so that it the brake should become worn or should slip for any reason it is quit-e possible for the bucket to move on down farther and ground on the bottom ol the ltower which would ordinarily slacken the cable. `It the ibrake slips slightly when the present invention is employed the cable is not slackened immediately because the weight 8O maintains its tension. It the bucket moves on down to the bottom of the tower, there is still a further period ot time during which the hoist may reverse, that is, the period it takes the weight 30 to move downward into contact with the bail 33. This time ordinarily sut'icicnt to permit the hoist to reverse and hence the cable is not slackened because ot the grounding ot the bucket. Viewed from the standpoint ot the permissible travel ot the hoisting apparatus during which the brake may operate, it will be clear that the invention provides a greater range ot distance of travel ot the hoisting apparatus during which the brake 22 may operate without slackenin the cable `and this is secured without requiring` any increased clearance tor the bucket at the bottom ot the tower.

Another condition under which the invention operates to maintain tension on the cable is that illustrated in Fig. 3 where the bucket is shown being dumped. When the bucket is raised to the top ot the tower the trunnions Q6 engage the guide 2'? and the bail 33 moves tho bottom of the bucket upwardly until the bucket is turned to the F ig. 3 position where the most of its weight is borne by the guides 27. Under these conditions there would ordinarily be a tendency tor the cable 24; to slacken but such slackening is prevented by the weight 30 which maintains the cable under tension. l-lere again the weight 30 becomes active to dislodge the bucket in the event it should stick in the guideways 27 for any reason. As the hoist reverses the weight 30 descends and hits the bail 33 a blow to drive the bucket downwardly in the event the bucket has not already moved.

lr" desired, the same construction can be employed in connection with the counterweights 25 but ordinarily this is not necessary and such construction has not been illustrated in the present drawings.

lt is to be understood that the structure shown is for purposes ot' illustration only and that variations may be made in it without departing trom the spirit and scope of the invention as delined by the appended claims.

I claim:

l. An automatic traction hoist having a hoisting drum, a cable passing over but not around said drum, a bucket on one end of the cableand a weight on the other to maintain the cable under tension to maintain it in tractive relation to the drum, and a compensating weight connected to the cable so that when the weight oi' the bucket on the cable is temporarily lessened the weight acts automatically to maintain the cable under tension.

i 2. An automatic traction hoist having a hoisting drum7 a cable passing over but not around the drum, a bucket on one end and a weight on the other end of the cable to main` tain it under tension to maintain it in tractive relation to the drum, a compensating weight yconnected to the cable on the bucket side thereof and slidable connections between the compensating weight and the bucket to permit the weight to move downwardly to maintain tension on the cable when the descent ot the bucket is arrested.

3. An automatic traction hoist having a hoisting drum, a. cable passing over said drum,v a hoisting bucket on one end and a weight on the other end of the cable to maintain it under tension to maintain it in tractive relation to the drum, means for causing the bucket to be dumped when it reaches a raised position, at which position the weight ot the bucket relieved trom the cable, and means for maintaining the cable under tension when the weight of the bucket is relieved from the cable during the dumping operation.

4f.. An automatic traction hoist having a hoisting bucket, a hoisting apparatus includ- 'mg a hoisting drum mounted above the path ot the bucket, a cable connected to a counterweight and passing over but not around the drum and connected at its other end through a compensating weight to the bucket whereby the cable is maintained under tension over said drum to maintain it in tractive engagement with said drum, and slidable connections between the bucket and the compensating weight permitting the weight to move down relative to the bucket to maintain the cable under tension when the weight of the bucket is relieved from the cable.

5. An automatic hoist having a hoisting bucket, a rigid bail pivoted thereto, rods extending upwardly from said bail, a weight slidably mounted on said rods, and a hoisting apparatus having a cable connected to said weight.

6. An automatic hoist having a. hoisting bucket, a rigid bail pivoted thereto, rods projecting upwardly from said bail and having stops on their ends, a weight .slidably mounted on said rods, springs positioned between the stops on the ends of the rods and said weight, and a hoisting apparatus having a cable connected to said weight.

7. An automatic hoist having a hoisting drum, a bucket, a cable `connected to said bucket and operated by said drum for raising and lowering said bucket, and means for automatically applying additional force t'o said bucket to cause descent thereof when the normal descent of the bucket is obstructed.

8. An automatic traction hoist having a hoisting drum, a cable passing over but not around said drum, a bucket connected to one end of the cable, a weight connected to the other end of the cable, the tractive eiort of said cable being dependent upon the cable being maintained under tension', and means for automatically applying additional force to cause descent of said bucket when the normal descent thereof is obstructed, said means also acting to maintain the cable under tension when the weight of the bucket thereon is relieved.

9. An automatic hoist having a hoisting bucket, means for raising and lowering said bucket, and a weight automatically brought into action by said raising and lowering means Afor striking said bucket to force the same downwardly when 'the bucket is obstructed in its normal `downward movement.

10. The combination in an automatic hoist of a hoisting bucket, means Jfor raising and lowering said bucket including a cable, a weight connected to the cable, and slidable connections between the weight and the bucket such that when the bucket is arrested during its descent the weight will move *downwardly to strike it.

In testimony whereof, I have subscribed my name.

WILLIAM E. HOWLETT. 

